Hi All,

Due to a slight miscommunication, I've purchased some Wurth DC-DC converters (#7491196212) which require a frequency of 200-400KHz on the input to function properly.

I'm wanting to utilise a 24v DC source as the input voltage, but need to know the simplest method of getting this to the correct the frequency required to make these DC-DC converters function as desired.

Thanks
Anubis.

 

Those are transformers not DC-DC converters. Another slight miscommunication, perhaps?

 

Those are transformers not DC-DC converters. Another slight miscommunication, perhaps?

Yes, true, on their site they're listed as "Transformer for DC/DC Converter", but that doesn't really answer the question at hand as to how one would obtain the desired frequency.

Thanks
Anubis.

 

What is the required specification?

 

From their data sheet (http://katalog.we-online.de/pbs/datasheet/7491196212.pdf) - pg2 - they state:

Input Voltage: 9-57 V (DC)
Switching Frequency: 200-400kHz

Thanks.
Anubis.

 

What's the specification for the DC-DC converter?

 

That's all I have I'm afraid - apart from that I'm trying to understand what's required to utilise these components in a circuit to take a 24VDC input and get a 12VDC output from these transformers.

Thanks.

 

And the output current should be?

 

The transformers are related to 1.6A on their 12v output, so somewhere close to this would be good as the current draw will be different for each place that these are being used, but the current draw should never exceed 1.3A

 

Why don't you just by some DC-DC converters?

It doesn't make sense to buy transformers and then try and find an application for them.

 

Why don't you just by some DC-DC converters?

Exactly - this is what the miscommunication was all about. For the project I'm working on, I have a readily available large selection of 24VDC power supplies and my project requires 12V and 5V source, I had thought to utilise these two versions of component to give me the 12V and 5V sources from the single 24V source.

Regardless, I've now got a bunch of these transformers and no way to utilise them; seeing as I'm in this predicament I thought it would be a good lesson anyway to see what's required to actually make these transformers do the job they're designed for and learn something in the process. Even if it ends up being more costly than simply buying a ready-made DC-DC converter (which I'll likely do in the future), at least this way I've not wasted these components and got something (better understanding) out of it.

Hope that clarifies why I'm perusing this angle rather than just dumping them and buying something off the shelf.

 

The thing is, you need someone to design a custom DC-DC converter using these transformers which is not a trivial task. Even building it would be tricky because you would be dealing with surface mount devices operating at Radio Frequency.

It's not just a case of sticking pulsed 24V at 200kHz+ in at one end and taking 12VDC out the other. The output must be regulated, protected against over-current and over-temperature, filtered to prevent RF entering whatever is being powered and the whole thing has to be designed and built in such a way that it doesn't act like a radio transmitter. This is why everyone (including professional electronic engineers) buys them off-the-shelf from Traco or similar.

 

Right, understood, well shall put this down to lesson learnt and thank you very much for your replies.

Thanks
Anubis.